1. Field of the Invention
The present invention relates to a new and improved method and apparatus for electrostatically charging fuel particles to provide better dispersion and mixing with an oxidizing agent such as air for subsequent combustion in an internal combustion engine, fuel burner and the like. In the prior copending application, a precombustion fuel conditioning device is provided for use with internal combustion engines wherein fuel is passed through a relatively fine wire screen which is charged with a positive potential with respect to the engine and the intake conduit. The voltage applied to the screen mesh may be relatively low and is conviently obtained from a twelve volt battery and the like. As the fuel air mixture passes through the electrostatically charged screen, the fuel particles are electrostatically charged by physical contact with the electrode and the charged particles repel one another and are attracted by the opposite charge on the hot intake manifold or conduit leading to the combustion chambers of the engine. The fuel particles strike the hot intake manifold wall surfaces and absorb heat from the wall surfaces which is utilized to vaporize the fuel droplets and this results in a better and more complete intermixing of the fuel and air providing better engine performance and fuel economy.
It is recognized that contact charging of the fuel particles passing through a charged screen mesh is an advantageous means for achieving better vaporization and mixing of the fuel and air or oxidizing agent. However, in the present invention, it is recognized that fuel particles or droplets flowing in a fuel stream may be electrostatically charged more effectively by means of induced charges on the particles which does not require physical contact between the fuel and the charging electrode. This type of field charging is provided by passage of the fuel stream through an electrostatic field so that the fuel particles accumulate charges through induction. This affords an advantage in that direct contact of the fuel particles with an electrode is not necessarily required and thus high flow resistance against the flow of fuel and oxidizing agent is reduced. With field induced charging, the flow of the fuel oxidizing agent mixture is relatively unimpeded by the electrode and excellent mixing and dispersion of the fuel within the oxidizing agent or air is achieved both by the induced static charges and by contact charging to some extent.
2. Description of the Prior Art
The prior art devices have utilized various means such as electrically heated grids or wires to improve fuel vaporization in a moving stream of air or other oxidizing agent. Catalytic surfaces have also been provided to promote better and more efficient precombustion mixing and interdispersion between the fuel and air mixture. Heater type devices have the disadvantage of requiring relatively large amounts of electrical energy for the heating elements and the catalytic devices are relatively expensive because of the high cost of applying expensive catalyst coating of flow confining surfaces of an induction manifold system.
In the present invention, the fuel particles are charged by an induction process as they move through an electrostatic field and once so charged, the particles in the stream tend to break apart and disperse outwardly to intermix with the oxidizing agent (usually air). The dispersed fuel droplets strike the hot wall surfaces of the intake manifold system of an engine and the fuel droplets are vaporized by the available heat from the hot manifold wall surfaces. The amount of electrical energy required to provide the electrostatic charging field is considerably smaller than that required to heat an electrical resistance heater or grid and a convenient source of high voltage potential for use on the electrodes of the present invention is usually available from an engine ignition coil when the invention is utilized with an internal combustion engine. Similarly, in fuel burners of various types, electric ignitions are often readily available and these provide a convenient source of electrical potential which may be effectively utilized for charging an electrode with high voltage to establish an electrostatic field around the fuel flow path.